Method of making a spherical container



Aug. 4, 1970 HQLCQMB ETAL 3,522,647

METHOD OF MAKING A SPHERICAL CONTAINER Filed Feb. 19, 1968 2Sheets-Sheet 1 INVENTORS MERW/V L. HOLCOMB B Y #JOH/V B. W/lVEG/JAD/VffiEl El j Ml-0/d/ A TTORNEYS Aug. 4, 1970 M. L. HOLCOMB EI'AL METHOD OFMAKING A SPHERICAL CONTAINER 2 Sheets-Sheet 2 Filed Feb. 19, 1968 ml Sm5 M a T0R/ .N M64 in m WHWJ T AW Q N a Q A W W 5 M M Y J, B m

United States Patent 3,522,647 METHOD OF MAKING A SPHERICAL CONTAINERMervin L. Holcomb and John B. Winegardner, Columbus,

Ohio, assignors to Lennox Industries Inc., a corporation of Iowa FiledFeb. 19, 1968, Ser. No. 706,412 Int. Cl. B21d 39/02 US. Cl. 29-463 3Claims ABSTRACT OF THE DISCLOSURE BACKGROUND OF THE INVENTION Theinvention relates to a spherical container and, more particularly, to amethod of making a spherical container from thin gauge metal.

Spherical containers are advantageous 'for storing and shippingliquified gases, for example, refrigerant. Such containers weigh lessfor an equivalent capacity than cylindrical containers. Normally afteruse, a refrigerant container is returned to the manufacturer 'for reuse.Because of weight, it is desired that the containers be made cheaply inthat they can be disposed of after use, rather than returned to themanufacturer.

One form of spherical container is shown in Pat. 3,050,207, granted Aug.21, 1962. However, to applicants knowledge, the device disclosed in saidPat. 3,050,207 has never been sold commercially.

The known methods of making spherical containers are not entirelysatisfactory. Heavy gauge metal can be formed in sections and thenbutt-welded along abutting edges to form a spherical container, as inPat. 2,118,388, granted May 24, 1938. The method is slow, expensive andwould be unsuitable where thin gauge metal is to be used for relativelyhigh volume production of spherical containers.

P-at. 2,113,060, granted Apr. 5, 1938, suggests a method of formingspherical receiver containers from thin gauge metal, whereinhemispherical receiver containers from thin gauge metal, whereinhemispherical male and female sections are provided having open endsformed with telescopically engaging portions. The open ends are joinedand then brazed to one another. The male and female sections must beformed by separate dies, thereby increasing fabrication costs.Difiiculties would be encountered in fitting the telescoping portions toone another and in maintaining desired roundness and fit in order toassure a good brazed joint and maintenance of relatively high pressureby the completed cot-ainer.

The interior of the completed spherical container must be free fromforeign materials. Since there is only a small opening in the spud topermit access to the interior of the container, it must be kept freefrom foreign materials during manufacture.

An object of the present invention is to provide an improved method offabricating spherical containers from this gauge metal, wherein thedisadvantages and deficiencies of prior constructions are obviated.

Another object of the present invention is to provide an improved methodof manufacturing a spherical container from thin gauge metal comprisingforming like hemispherical sections with inturned flanges at the openends, abutting the inturned flanges at the open ends of the icehemispherical sections and welding the sections togetherj Other objectsand advantages of the present invention will be made more apparenthereinafter.

BRIEF DESCRIPTION OF THE DRAWING A preferred embodiment of the presentinvention is shown in the drawing, wherein:

FIG. 1 is a perspective view of a spherical pressure cylinder made inaccordance with the method of the present invention;

FIG. 2 is a cross-sectional view of the spherical pressure cylinder ofFIG. 1, but with the control valve omitted;

FIG. 3 is an elevation view of the apparatus for making the sphericalpressure cylinder;

FIG. 4 is a plan view of the apparatus of FIG. 3;

FIG. 5 is a View of one chuck of the apparatus of FIGS. 3 and 4 takengenerally along line 5-5 of FIG. 3 and illustrating the relationship ofthe guide means to the welding head; and

FIG. 6 is a cross-sectional view of the chucks of the apparatus of FIGS.3 and 4, with a spherical pressure cylinder being illustrated inposition for assembly, taken generally along line 6-6 of FIG. 5.

DESCRIPTION OF THE PREFERRED EMBODIMENT Referring now to FIGS. 1 and 2of the drawing, there is illustrated a spherical container 1.0 made inaccordance with the present invention. The spherical container 10 is ofthe lightweight disposable type, which is adapted to be disposed afteruse. The container is particularly adapted for containing material underpressure, for example, liquified gas, refrigerant or the like.Essentially, the cylinder 10 comprises a pair of like hemisphericalsections 11 and 12, joined to one another; Aflixed to the hemisphericalsection 12 is a footring 14 which may be formed or stamped from a thingauge sheet material and then spot welded, or otherwise secured to thehemispherical section 12. The handle portion 16 may be suitably stampedor formed from thin gauge sheet material to provide the openings 17 and19 therein, and then formed to shape. The formed handle I16 is thenspot. welded, or otherwise suitably secured to the hemispherical section11. A spud or fitting 20 is secured to an opening in the top portion ofthe hemispherical section 11 and a suitable control valve 22 is securedwithin the spud 20. The valve 22 controls the discharge of refrigerantfrom within the container in either liquid or vapor form and if desired,the valve 22 may include a spring loaded relief device.

With reference to FIG. 2, it is noted that the two hemisphericalsections 11 and 12 are each provided with an inturned annular flange 24and 25, respectively. The flanges 24 and 25 are formed such that theexterior surface of each lies generally in the plane of the open end.The footring 14 is secured to the hemispherical section 12, such that aplane containing the exterior surface of flange 15 of the footring 14would be substantially parallel to the plane of the exterior surface ofthe inwardly turned flange 25. The spud 20 is secured to thehemispherical section 11 at substantially right angles to the plane ofthe exterior surface of the inwardly turned flange 24. The handle 16 isafiixed to the hemispherical section 11 concentric to the spud 20.

The spherical container 10 is manufactured from relatively thin gaugemetal stock, for example, steel or aluminum, though steel is presentlypreferred because of its cheaper cost. The hemispherical sections 11 and12 are identical and are formed from thin gauge sheet material on theorder of .030" thick. During trimming or cutting to size of the sheetstock, half of the stock may have a hole formed therein, which willprovide opening for the reception of a spud at a later time. Thehemispherical sections 11 and 12 may be then drawn to form and theinwardly turned flanges 24 and 25 may be provided by a separate stampingor forming operation. It is preferred that the inwardly turned flangeslie substantially in the plane of the open ends of the hemisphericalsections, that is, the exterior surface of the annular inturned flangeof each hemispherical section should lie in a plane. This arrangementprovides planar abutting contact between the inwardly turned flanges 24and 25 during subsequent fabrication and assembly to form the sphericalcontainer. The inwardly turned flanges appear to rigidify thehemispherical section and minimize egging or out of round distortion ofthe hemispherical sections before joinder to one another.

After the hemispherical sections 11 and 12 have been formed, and theinwardly turned flanges 24 and 25 properly completed, the hemisphericalsections are separately processed. The footring 14 is connected to thehemispherical section 12, as by spot welding, in such manner that aplane through the bottom of the footring as viewed in FIG. 2 is parallelto a plane through the outer surfaces of the internal flange 25.

The spud 20 is inserted into the opening in the hemispherical section 11and secured thereto, with the axis of the spud at right angles to theplane of the inwardly turned flange 24. The spud 20 subsequently servesas a locator for the handle 16, which is concentrically disposed aboutthe spud 20 and joined to the top of the hemispherical section 11, as,for example, by spot weld- With reference to FIGS. 36, there is shownapparatus for joining the hemispherical sections to one another. Theapparatus comprises a suitable framework 32 having a first track meansor guideway 34 and a second track means or guideway 36 formed thereon.Slidably supported on the first trackway 34 is a support head 36, whichrotatably journals a chuck 38. Power drive means 40 are provided toreciprocate the support head 36 in trackway 34. The power drive means 40may comprise a power ram and cylinder operatively connected to a sourceof power, for example, a source of pressurized air. It will beunderstood that hydraulic source may be substituted for the pneumaticsource, if desired.

Slidably carried on the trackway 37 is a support 42 for a second chuck44. The support 42 is adapted to be reciprocated in the trackway 37 bypower drive means 46, which may include a power ram and cylinderoperatively connected to a pneumatic or hydraulic power source. Carriedon the support 42 is a drive means 48, which is operatively connected toa variable speed gear reduction mechanism for rotating the chuck 44 at apredetermined rate of speed. As illustrated, the electric motor 48 isconnected to the reduction mechanism 50 by means of a chain drive 52.

Operatively disposed between the cooperating chucks 38 and 44 is awelding mechanism 54, which is ada ted to be moved toward and away fromthe work held within the chucks 38 and 44. The welding mechanism 54 maybe of a conventional type, for example, a metal inert gas type, and mayinclude a wire feed mechanism. A feature of the apparatus is theprovision of a guide finger or guide mechanism 56 on the welding head,for guiding the welding head along the plane of joinder between theabutting hemispherical sections of a spherical container. The weldingmechanism 54 is slidable in a trackway supported on plate 57 that issuitably secured to the framework 32. Trackway 55 guides the weldingmechanism for movement toward and away from the work to be welded. Asseen in FIG. 5, the guide 56 is operatively associated with the weldinghead 54, so as to cause tracking of the welding head along the joinderline between the hemispherical sections 11 and 12 both laterally of atrue joinder plane, as well as toward and away from the work. Thoughvariations are small, they can be important in adversely affecting thequality of the weld. The

guide means 56 assumes a superior, uniform weld during rotation of thechucks 38, 44 and work (hemispherical sections 11 and 12 to be joined)carried therewith.

The hemispherical section 12 is disposed within the chuck 38, such thatthe footring 14 is over the adaptor 39 secured to the back-up plate 41of chuck 38 and the planar flange 15 on the footring 14 is carried bythe three spring loaded detent mechanisms 60, 61 and 62 on the back-upplate 41 of the chuck 38. The detent mechanisms 60, 61 and 62 are spaceduniformly in a circle about the axis of the chuck 38 and each includes aplunger mechanism 66, 6'7 and 68, which is spring loaded to permitdetachable connection and retention of the hemispherical section 12within the chuck or holder means 38. The hemispherical section 12 isretained in such manner that the plane of the internal flange 24 isperpendicular to the axis of rotation of the chuck 38, with the retainerring 43 of the chuck 38 adjacent to but spaced from the flange 25. Theretainer ring 43 is secured to the back-up plate 41 by means of ribs 45.

The hemispherical section 11 is disposed within the chuck 44 andretained therein with the flange 25 in abutting relationship with theinwardly turned flange 24 of the hemispherical section 11. The chuck 44is provided with an adaptor 70 which has a recess 72 in the forward endthereof for receiving the spud 20. The adaptor 70 receives the spud soas to center the section 11 within chuck 44 and to orient the sectionwith the plane of the open end at right angles to the axis of rotationof the chuck 44. The adaptor 70 includes a passage 74 thereincommunicating with the opening in the spud 20 for venting the interiorof the spherical container 10 to the atmosphere during fabrication.Adaptor 70 is secured to backup plate 76 of chuck 44. The retainer ring78 is secured to the back-up plate 76 by ribs 79. The retainer ring 76is constructed and arranged to engage a hemispherical section 11adjacent to but spaced from the flange 24. The chucks 38 and 44 areseparated. A rotary grounding means 80 is operatively secured to thechuck 38 for grounding the welding mechanism 54 in use.

To fabricate a container, operator positions a hemispherical section 12in chuck 38. A hemispherical section 11 is positioned with a chuck 44with the spud 20 in engagement with the recess 72 in the adaptor 70. Thepower drives 40 and 46 are then actuated to move the chucks 38 and 44toward one another, so as to move the internal flanges 24 and 25 of therespective sections 11 and 12 into abutting relationship with oneanother.

The operator then actuates a suitable control to move the weldingmechanism 54 toward the chucks so as to move the guide 56 into contactwith the plane of joinder between the two hemispherical sections 11 and12. The rotary drive 48 is actuated to rotate the chuck 44. Because ofthe frictional contact between the cooperating hemispherical sections,the chuck 38 will also be rotated. The guide 56 will guide or track forthe welding head, so as to maintain the disposition of welding head withrespect to the Work, so as to produce uniform weld. It has been foundthat by virtue of the cooperation of welding head with the two inwardlyturned flanges 24 and 25, a uniform weld will be formed at the surfaceof the spherical container, and no portion of the inwardly turnedflanges will be broken off and fall into the container. An importantconsideration in fabrication of the spherical container is that theinterior of the containers 10 be free from foreign material, as the onlyopening in the finished container is that in the spud 20. Such openingis relatively small and it is, therefore, diflicult to effect cleaningof the interior of the container. Therefore, it is most important thatno contaminants or foreign materials enter the interior of the sphericalcontainer during fabrication.

After fabrication of the spherical container as viewed in FIG. 2, thecontainer is air cleaned and pressure tested. Those units satisfactorilypassing the pressure test are then dried, painted, and a valve isapplied to each. The containers are then ready for filling.

The spherical container resulting from application of the presentinvention is made from thin gauge sheet metal, and can be readilyproduced at high volume and at relatively low cost. The completedspherical container is of high quality. Such container is lightweight,readily handled whether full or empty, and may be disposed after use.

By virtue of performing the welding of the hemispherical sections and atthe same time venting the interior of the container through the openingin the spud to the atmosphere, there is no undesirable pressure build-upwithin the spherical container. The inwardly turned flanges cooperatewith one another to provide a uniform weld without any burn-off orsputtering of welding material into the interior of the container duringfabrication. Thus, the interior of the finished container is essentiallyfree from foreign materials.

While we have described a presently preferred embodiment of ourinvention, it will be understood that the invention is not limitedthereto, and it can be embodied within the scope of the followingclaims.

We claim:

1. A method of manufacturing a spherical container from thin gauge metalcomprising the steps of forming hemispherical sections, each having aninturned annular flange at the open end thereof, with an opening in oneof said hemispherical sections, the axis of said opening lyingperpendicular to the plane of the open end of said one hen1- isphericalsection, aflixing a spud in said opening such that the axis thereof isperpendicular to the plane of the open end of said one hemisphericalsection, securing a handle ring to said one hemispherical sectionconcentric to the spud, securing a footring to the other hemisphericalsection in a plane parallel to the plane of the open end of said otherhemispherical section, abutting the inturned annular flanges at the openends of the hemispherical sections, centering said other hemisphericalsection prior to joinder by means of the footring and centering said onesection prior to joinder by means of the spud, whereby the inturnedflanges abut one another substantially about the entire peripheriesthereof, and joining the hemispherical sections to form a sphericalcontainer open to the atmosphere only through the spud.

2. The method of claim 1 including the steps of forming the internalflanges such that the exterior surfaces thereof lie in the plane of theopen end and abutting the hemispherical sections with the exteriorsurfaces of the internal flanges being in engagement substantially aboutthe entire peripheries thereof.

3. The method of claim 2 including the step of welding the hemisphericalsections in the region of abutment of the hemispherical sections whileventing the interior of the spherical container through the spud topermit release of pressure from within the spherical container.

References Cited UNITED STATES PATENTS 2,113,060 4/ 1938 Sandberg 29-4632,118,388 5/1938 Zerbe. 2,171,972 9/1939 Debor. 2,445,268 7/ 1948Hodgins 29463 3,050,207 8/ 1962 Oxenham 220-94 XR JOHN F. CAMPBELL,Primary Examiner R. B. LAZARUS, Assistant Examiner U.S. Cl. X.R.

